The FIA has publicly confirmed the results of Formula 1’s ADUO assessments, establishing Red Bull’s internal combustion engine as the benchmark ahead of Mercedes. Yet understanding what the FIA ADUO ranking actually means is more complicated than simply identifying which manufacturer appears at the top, because the mechanism was deliberately designed to measure only specific aspects of the highly complex 2026 power units.
The governing body is confident in the accuracy of its analysis. Nikolas Tombazis, the FIA’s Single-Seater Director, has described the methodology as incredibly robust based on the quality of the available data. However, the system can only produce conclusions according to the parameters on which ADUO was originally designed and agreed with the manufacturers. Those parameters do not attempt to reproduce every element that determines the real-world performance of a modern Formula 1 power unit.
FIA ADUO results confirm Red Bull ahead of Mercedes
After a lengthy wait, the FIA finally published the results from the first and second evaluation periods assessing power-unit performance. The outcome essentially confirmed the same hierarchy that had emerged after the Monaco Grand Prix, with Red Bull retaining its position at the top.
The result was not particularly surprising because only Ferrari and Audi had introduced changes before Zandvoort. Those developments were considered relatively minor and were not expected to deliver a large horsepower increase. Ferrari has nevertheless been using the opportunities created by the regulations to address its deficit, with its ADUO-2 engine development targeting another performance step.
The FIA announcement also represented the first official confirmation from the governing body that Red Bull’s internal combustion engine is the reference point on the grid, ahead of Mercedes. That conclusion attracted particular attention because the Mercedes unit had widely been regarded as Formula 1’s strongest power unit.
The initial finding prompted Red Bull to request a review of the data. That process contributed to the delay in publication, but the subsequent review confirmed the original ranking produced by the FIA.
Nikolas Tombazis underlined the governing body’s confidence after the completion of the second assessment period, explaining: “Based on the quality of the data, the analysis is incredibly robust, which gives us a high level of confidence in our conclusions.”
Ferrari’s position within that hierarchy has already made the ADUO mechanism particularly important for Maranello, with the FIA’s ADUO rankings placing Ferrari more than four per cent behind the benchmark.
Why the FIA ADUO ranking focuses on the combustion engine
The crucial point is that ADUO does not provide a complete ranking of Formula 1 power units. It measures what the manufacturers and governing body agreed should be assessed when the mechanism was designed last year.
During the first part of the season, the FIA collected a huge quantity of information. The governing body also benefits from direct access to data that rival manufacturers cannot see and would instead have to estimate through alternative methods.
Two closely related principles are particularly important when trying to understand the results. First, the ADUO hierarchy is based on the power produced by the internal combustion engine. The electrical side of the power unit plays only a marginal role in determining the ranking itself.
When the stakeholders originally discussed how ADUO should operate, Nikolas Tombazis explained that the electrical system was deliberately identified as the area in which manufacturers should be free to compete more aggressively through development.
That approach makes sense within the context of the 2026 regulations, which have dramatically increased the importance of the electrical component of the Formula 1 power unit. Manufacturers were given greater freedom to gain an advantage through the quality of their work on that side of the package, while specific catch-up mechanisms were created for the combustion engine to prevent a manufacturer from remaining trapped with a major deficit.
This distinction is particularly important when interpreting Ferrari’s overall performance. The Scuderia’s recent difficulties have shown how hybrid deployment and software management can affect the SF-26 even when an ADUO assessment is focused primarily on combustion-engine output.
The historical reasoning behind F1’s ADUO rules
The philosophy also has to be understood in the historical context in which the regulations were conceived. At that stage, the automotive industry was convinced that electrification represented the future and that the electrical side would become a key technological battleground between manufacturers.
The intention was therefore to reward whichever manufacturer performed the best work in that area rather than creating a mechanism that automatically allowed competitors to close every deficit.
Just like the wider Formula 1 technical regulations, the ADUO framework was discussed, shared and ultimately approved by the manufacturers themselves. It was not simply imposed on them after the current generation of power units had already reached the track.
This context helps explain why an internal combustion engine ranking cannot automatically be interpreted as a complete power-unit ranking. Power delivery, electrical deployment and the interaction between the different systems all contribute to the performance that is ultimately visible on track. Ferrari’s broader technical development of the SF-26 has repeatedly demonstrated how interconnected those areas have become under the 2026 rules.
FIA proposed a more detailed ADUO formula in 2025
There is also a second important element behind the current methodology. As the complexity of the new power-unit formula became increasingly apparent, the FIA proposed changing the way every engine would be assessed during the spring of 2025.
The governing body’s idea was to add several secondary parameters to the calculation. These included turbocharger dimensions, exhaust pressure and plenum temperature, all of which could potentially help provide a more complete indication of the true performance potential of a power unit.
The manufacturers rejected that proposal.
Adding those parameters would clearly have made the assessment considerably more complicated, but it would also have produced a broader picture by taking the specific characteristics of each manufacturer’s design into account. That matters because not every Formula 1 power unit necessarily produces its performance in the same way.
Different concepts can have different operating characteristics, which is one reason why a straightforward horsepower comparison cannot capture every technical strength and weakness. The significance of that distinction is also visible in Ferrari’s development programme, where the 067/6 ADUO-2 evolution involves changes aimed at improving the engine’s performance characteristics, rather than treating power as a single isolated number.
Torque curves and turbo behaviour complicate engine comparisons
An engine does not necessarily develop torque in the same way as a rival design, at the same load or at the same engine speed. Those differences can significantly influence how each power unit behaves during different phases of a lap.
For example, these engines do not generate a large turbo load while stationary. That characteristic also helps partly explain some of the difficulties seen at race starts, which are not caused exclusively by the removal of the MGU-H.
Design choices made within the power unit can also influence how the rest of the car is conceived. A Formula 1 car remains a highly delicate compromise between different technical departments, meaning an engine decision cannot always be separated cleanly from packaging, aerodynamics or the wider vehicle concept.
Those were among the types of parameters that could have been included in a more sophisticated ADUO methodology. Ultimately, however, they were rejected in favour of keeping the evaluation process more direct and easier to manage.
How the FIA actually measures power for ADUO
The current system therefore focuses on measured power output. A standard dedicated sensor positioned at the engine output is used as the foundation of the assessment. The underlying principle is similar to the method used in the World Endurance Championship when assessing powertrain potential.
Once that figure has been obtained, the FIA also knows in real time how much power the electric motor is producing through information read from the control electronics. This allows the governing body to calculate the contribution coming from the internal combustion engine.
However, the FIA is not simply searching for the highest peak-power figure recorded during a Grand Prix weekend. Its analysis is broader, with adjustments applied across several areas of a lap because the information is collected directly on track rather than on an engine dynamometer.
That distinction is fundamental to understanding why the ADUO result can differ from impressions formed by watching cars on the circuit or studying individual straight-line performance. Ferrari’s own experience has demonstrated why a V6 horsepower deficit does not necessarily explain the complete power-unit picture.
Why some parts of an F1 lap carry more weight
Nikolas Tombazis explained the principle in April: “Power is calculated in a lap-weighted way, so where power is more important it has more weight than where power is less important. Typically at the beginning of a straight, power is more important than at the end of the straight, for example.”
The logic is understandable. Towards the end of a straight, aerodynamic performance and aerodynamic efficiency become increasingly influential, making it more difficult to separate the effect of the engine from the characteristics of the car itself.
The complication is that each manufacturer can approach its torque curve differently. There is no guarantee that every engine manufacturer has designed its power unit around exactly the same philosophy, particularly in a technical cycle where the interaction between the electrical system and the combustion engine has become decisive.
Having additional power available when a car reaches superclipping can clearly be beneficial, for example, but manufacturers may not all have approached that problem in the same way. This is another reason why the FIA attempts to average performance across several sections of a lap rather than taking one absolute maximum value.
Why Mercedes can still hold an advantage despite Red Bull’s ADUO lead
The manufacturer capable of managing the electrical component most effectively can therefore gain a clear advantage. As a consequence, outright combustion-engine power becomes subordinate to the efficiency with which the complete power unit has been conceived and operated.
This is precisely the area in which Red Bull considers itself to be at a disadvantage and Mercedes believes it holds an advantage. The FIA ADUO ranking can therefore identify Red Bull as the combustion-engine benchmark without necessarily concluding that Red Bull possesses the strongest complete power unit in every respect.
It also helps explain why judging the 2026 cars solely by horsepower rankings can be misleading. Electrical energy management, deployment and the integration between the hybrid system and combustion engine can alter the competitive picture significantly. Ferrari has faced the same challenge while trying to optimise the relationship between engine performance, drag and hybrid deployment on the SF-26.
FIA acknowledges the ADUO system can evolve
None of this means the current ADUO mechanism is perfect. Nikolas Tombazis has already made clear that the measurement methodology itself is expected to evolve over time as the FIA and manufacturers gain more experience with the new regulations.
What the present system does demonstrate is that the FIA is assessing precisely the elements around which ADUO was originally conceived, according to a framework that was agreed with all of the power-unit manufacturers.
Nikolas Tombazis acknowledged both sides of the situation: “I think our assessment, in my opinion, has proved very accurate. That said, has everything gone well? No, because obviously there is dissatisfaction and so on. Do we need to think about improvements for the future? Yes, I would say so.”
The distinction is therefore essential when interpreting the FIA’s results. Red Bull can legitimately sit at the top of the ADUO combustion-engine ranking while still believing it has ground to recover in electrical performance, just as Mercedes can trail in the measured ICE hierarchy while benefiting from strengths elsewhere in its power-unit concept.
ADUO was designed to measure and regulate a specific part of the competitive equation, not to produce a definitive ranking of every aspect of Formula 1’s 2026 power units. That difference is what makes the published numbers both meaningful and considerably more complex than a simple list of which manufacturer has the best engine.
Leave a Reply